Understanding Exception Class
An exception can be defined as any unusual event that requires special handling in your PeopleCode program. This could include some kind of hardware failure, such as trying to write to a printer that's been turned off, or a software failure, such as trying to divide by zero. You can also detect your own errors, and use the Throw statement to construct an exception.
Exception handling is the processing you initiate when an exception occurs. You can handle errors in PeopleCode using the Catch statement. The places in your code where you want exceptions handled must be enclosed by the Try and End-Try statements.
The Exception class encapsulates exceptional runtime conditions. It can be used with most PeopleCode programs.
Note: The Exception class does not work with any of the PeopleSoft APIs, that is, the classes whose objects are declared as type ApiObject. This includes the Tree classes, the Query classes, Search classes, and so on.
The process of error handling can be broken down as follows:
An error occurs (either a hardware or software error).
The error is detected and an exception is thrown (either by the system or by your program).
Your exception handler provides the response.